Changes in the spine density on apical dendrites of pyramidal neurons in the motor area of the cerebral cortex after callosotomy: a study by a modified Golgi-Cox method in the mouse.
Changes in the number of spines on apical dendrites of pyramidal neurons in layers III and V of the motor area of the cerebral cortex were examined in the young adult mice (30-60 days old) by a modified Golgi-Cox method and laser scanning microscopy on the 1st, 6th, 10th and 12th days after callosotomy. The anterior part of the callosal body, including rostrum, genu and truncus corporis callosi, was sectioned with a razor blade. The numbers of spines on apical dendrites and their oblique branches of pyramidal neurons were counted at the level of layer II for layer III pyramidal neurons and at the level of layer III for layer V pyramidal neurons. The density of spines was increased on all these dendritic parts during 10 days after callosotomy; the diameters of spine stems and dendrites were also increased. These changes, however, appeared to be transient as they were decreased almost to normal level on the 12th day after callosotomy.
Shimada
M
M
Department of Anatomy, Osaka Medical College, Japan.
Negi
T
T
Itano
T
T
Hayasaki
H
H
Konishi
M
M
Watanabe
M
M
Murakami
T H
TH
D000818:Animals; D003337:Corpus Callosum / Q000601:surgery*; D003712:Dendrites / Q000502:physiology* / Q000648:ultrastructure; D051379:Mice; D018613:Microscopy, Confocal; D009044:Motor Cortex / Q000166:cytology / Q000502:physiology*; D017966:Pyramidal Cells / Q000502:physiology* / Q000648:ultrastructure; D013194:Staining and Labeling / Q000379:methods